The invention relates to a method and apparatus for repairing plastic and vinyl materials and more specifically to a method utilizing a heat curable compound and a hand tool which provides a narrow, accurately controllable heated jet of air to effect the curing of such compound.
Plastic and particularly vinyl material has become widely accepted as an upholstery material for furniture and automotive seats as well as a covering for luggage, purses and miscellaneous clothing articles such as boots. Among its advantages are its imperviousness to water, its ability to remain flexible over a broad range of temperatures and the variety of colors and finishes in which it is easily produced. By comparison to natural hide materials such as leather, vinyl materials exhibit highly uniform color and thickness which obviates the necessity of matching and piecing, are generally more tear resistent and cost substantially less.
Like any furniture or article covering, the plastic material will generally be used for an extended period of time and will eventually sustain damage. Pointed objects such as automobile keys and childrens toys or heated objects such as cigarettes are often the cause of such damage. Although the damage caused by such abuse is usually confined to a small area, it is often on an exposed, highly visible portion of the article. Most consumers have found it expensive and therefore impractical to replace the entire plastic panel containing the damaged area with new material.
In order to eliminate both the high cost of replacement and the unattractive damaged area itself, a number of in situ plastic repair procedures and devices have been developed. Typical of such consumer-oriented repair kits are those disclosed in my issued U.S. Pat. Nos. 3,713,926 and 3,887,413. Such kits include heat curable plastic or vinyl repair compounds which is placed in and cured in the damaged area by the application of heat.
A problem of such in situ repair kits can be generally characterized as the inexperience of the amateur (i.e., consumer) plastic fabric repairer. More specifically, this problem centers on the application of an appropriate quantum of heat energy which is sufficient to properly cure the patching compound, but which is not so great as to harm the surrounding, initially undamaged material. One solution to the problem of limiting the quantum of heat energy supply is disclosed in my copending U.S. Patent Application, Ser. No. 862,921, now U.S. Pat. No. 4,181,547. Repairs utilizing the process and apparatus described in this patent application are, however, preferably limited to those damaged areas which can be repaired with a single application of the tool.
Repair of large damaged areas or areas with highly irregular shapes remains a problem, inasmuch as is preferable to heat and cure the entire patch simultaneously. Although some attempts have been made to utilize heat guns of the type designed to cure heat-shrinkable tubing or for similar applications, they have generally been found to produce too large a quantity of heated air at too high a temperature, such that damage to the surrounding material results.